1. Field of the Invention
This invention relates to an improved torque strut for resisting the torque developed by a transverse mounted engine for front wheel drive vehicles and for damping engine vibrations.
2. Description of the Prior Art
In vehicles with the internal combustion engines mounted in a transverse position for front wheel drive arrangements, the engine develops a torque which tries to rotate the engine relative to the frame. The effect is most noticeable when the transmission is in either a forward or reverse mode of operation. The torque effect is extremely objectionable because it is directed in such a way as to cause the vehicle to pitch fore and aft. Therefore, it has been proposed to oppose the torque or pitching effect of a transversely mounted engine by means of a rigid strut having limited cushion effect when mounted between a suitable point on the engine or powertrain and an attachment point on the vehicle frame. The purpose for the rigid strut is to react in either tension or compression depending on whether the engine is in forward or reverse drive. One such installation is found in Harlow Jr. et al U.S. Pat. No. 4,240,517 issued Dec. 23, 1980.
It is also recognized, in some vehicle applications, to provide a vertically mounted hydraulic damper used to damp engine vibration. Another type of shock absorber, although not hydraulic in operation, embodies a plunger disc in which the motion in either direction is opposed by a coil spring so that the plunger rod connected to the piston will be opposed in its motion in either direction by one or the other of the coil springs. Such a structure is disclosed in Papousek U.S. Pat. No. 3,682,462 issued Aug. 8, 1972.
A problem with the transversely mounted engines is the necessity of an engine mounting torque strut to oppose engine pitching generated by engine torque. Such device generally could introduce undesired engine vibration into the passenger compartment. Additionally, this type of device requires flexible mounting at the engine also, where the high heat will shorten the life of the mounting. A further problem with the small front wheel drive vehicles is the space limitation in the engine compartment which does not permit additional devices to overcome the foregoing problem. Thus, a hydraulic shock absorber in conjunction with the prevailing torque strut at this location is not feasible.